1. Field of the Invention
The present invention relates to a paper feeding apparatus and more particularly to a paper feeding apparatus preferably used for an image information reading apparatus in facsimile or the like machine.
2. Description of the Prior Art
A conventional image information reading apparatus incorporated in facsimile or the like machine is generally constructed such that image information on an original is read using image information reading means which is held immovably, while the original is transferred by a paper transferring device at a subscanning speed. A plurality of originals on the original holding board are fed one by one, as adjacent originals are transferred while keeping a certain gap therebetween.
A paper transferring device usable for the conventional image information reading apparatus incorporated in facsimile or the like machine is schematically illustrated in FIG. 1.
A conventional image information reading apparatus comprises a paper feeding roller 2 located in the proximity of the lower end of the inclined original holding board 1, a platen roller 3 and a pair of discharging rollers 4 disposed below the paper feeding roller 2 at a predetermined distance as measured from the latter. Further, a pad 5 is brought in pressure contact with the outer surface of the paper feeding roller 2 and a platen glass 6 is disposed opposite to the platen roller 3 while coming in contact with the latter. The conventional image information reading apparatus as constructed in the above-described manner is operated by way of the steps of taking one original 7a from a stacked layer of originals on the original holding board 1 through cooperation between the paper feeding roller 2 and the pad 5, feeding it to the area defined between the platen roller 3 and the platen glass 6, and reading image information on the original 7a through the platen glass 6 with the aid of a sensor 8 while transferring it toward the discharging rollers 4 by rotating the platen roller 3. Further, in the image information reading apparatus a fluorescent lamp 9 is disposed in the area between the paper feeding roller 2 and the platen roller 3 on the lefthand side of the original transferring passage as seen in FIG. 1 sensor 10 such as a light beam receiving element or the like is disposed at the position located opposite to the fluorescent lamp 9 relative to the original transferring passage whereby both the fore and rear ends of the original 7a are detected.
In the conventional image information reading apparatus the original 7a is required to have the same moving speed as sub-scanning speed while it is transferred by means of the platen roller 3. On the other hand, to form a gap between the previous original 7a and the next original 7b, the moving speed of the subsequent original 7b should be lower than that of the previous original 7a taking into consideration breakage of roll paper and other malfunctions, which is reflected by variations in the gap as detected by sensor 10.
To meet the above-described requirements an arrangement is made for the image information reading apparatus so as to rotate the paper feeding roller 2 and the platen roller 3 with the aid of separate driving mechanisms in such a manner that the paper feeding roller 2 has a peripheral speed lower than that of the platen roller 3. Alternatively, the paper feeding roller 2 is operatively connected to power supply via clutching means so that after the previous original 7a is taken by the platen roller 3, feeding of the subsequent original 7b is interrupted by turning off the clutching means and allowing the paper feeding roller 2 to rotate idly.
Accordingly, it has been found with respect to the conventional image information reading apparatus that designing of the apparatus in smaller dimensions can be achieved only within a limited extent. Further, the apparatus is complicated in structure and is manufactured at an expensive cost.